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Alsa for the IBM Thinkpad 600 Laptop (possibly also for later versions)

The Thinkpad 600 has a CS4237B, which is very compatible with both the CS4232 and the CS4236 driver. The consensus of many users seems to be to test the the CS4236 driver first. If you have quality problems (you shouldn't), try the CS4232 instead. The Linux 2.4 kernel also has a CS4232 driver which works, though it may not be as good as the Alsa driver (I tested it, but not extensively).

A key thing to remember is that the Thinkpads are somewhat odd in their approach to ISAPNP. For instance, at least in Linux 2.4, pnpdump doesn't work and using the isapnp=1 settings can get you into trouble.

The recommendations I have seen are:


Recommendation 1

Ensure that "((ThinkPad Simple Boot))", AKA "Quick Boot" is DISABLED. If you do not do this, the PNP BIOS may not appropriately set the resources for the CS4232, and you'll always get a Device Busy or not found error when you modprobe the driver no matter what settings you give.

Recommendation 2

Use the PS2.EXE utility (sadly, you have to boot into DOS to do this) to set and verify the resources used by the soundcard (and make sure it's enabled). That is, check the AUDIO and AUDIOCTRL parameters. The MIDI parameter (for the mpu) can be disabled. You don't need it unless you're hooking to external MIDI devices. PS2.EXE is available on the IBM site, click downloads after going to the IBM support link listed under ThinkPad.

You may instead be able to use "lspnp -v" and "setpnp" to view and configure these settings (lspnp and setpnp are distributed in the PCMCIA-CS package). To use lspnp and setpnp, you might have to have build the kernel with the PNP-BIOS configuration option enabled. This option is shown as experimental in the 2.4 kernels, up to 2.4.20 anyway. Also, look at the tpctl link on the ThinkPad page.

Recommendation 3

You need to have the source for the kernel to build the alsa drivers (I think at least alsa 0.9 is recommended for linux 2.4). It's best (maybe imperative for the TP600) to run ./configure with the --with_isapnp=0 option. The kernel source code should also have been built with the configuration setting "ISAPNP BIOS" disabled. If you don't totally disable ISAPNP support on the TP600, when the driver starts it may try to use the isapnp functions to determine resources automatically. This always seems to fail on my TP600 (and others as well, I gather) for the same reason that pnpdump doesn't do anything. The options I used are

./configure --with-isapnp=0 --with-sequencer=yes --with-cards=cs4232,cs4236

Recommendation 4

Immediately after "make install" for the driver, do a "modprobe cs4236 port=PORT cport=CPORT irq=IRQ dma=DMA dma2=DMA2". You found PORT, IRQ, DMA, and DMA2 using PS2.EXE (or lspnp -v), right? My machine's lspnp -v shows

0e CSC0000 Crystal PnP audio system CODEC
  port 0x530-0x537
  port 0x388-0x38b
  port 0x240-0x253
  irq 5
  dma 1
  dma 0

0f CSC0000 Crystal PnP audio system control registers
   port 0x538-0x53f

so I used

modprobe snd-cs4236 port=0x530 cport=0x538 irq=5 dma1=1 dma2=0

to test with. Note that I left my Crystal PnP audio system MPU-401 disbled in PS2.EXE (I think you only need the MPU-401 enabled if you are going to use the external MIDI port). Also note that, to get lspnp to work, I compiled the (2.4.20-ac2) kernel with

 # CONFIG_ISAPNP is not set

in the .config file.

Recommendation 5

If this doesn't work and you get several messages, one ending with some phrase like "device not found or busy", the next one saying something like "hint: this may be caused by incorrect resource settings" the problem might be the resources (check PS2.EXE and lspnp). Or it might be that quick boot is enabled. Or maybe the isapnp is enabled, either because you didn't specify the --with_isapnp=0 option, or you did, but the kernel was compiled with its own ISAPNP configuration enabled (in which case the alsa drivers will use the kernel's internal isapnp, NOT the settings you specify to modprobe). If you think resource settings are the problem, recompiling the alsa drivers using --with_debug=detect or --with_debug=full may help. If you really want some debug messages, edit the sound.h file in the kernal drivers and recompile the kernel (you may need to manually modprobe soundcore and snd to prior to attempting the load of cs4236 to see this).

Recommendation 6

Otherwise, modprobe should have gone through with no errors. If you do an

lsmod | grep snd

you should see something like this:

snd-cs4236              2160   0  (unused)
snd-cs4236-lib         10160   0  [snd-cs4236]
snd-opl3-lib            5360   0  [snd-cs4236]
snd-hwdep               3376   0  [snd-opl3-lib]
snd-cs4231-lib         13616   0  [snd-cs4236 snd-cs4236-lib]
snd-pcm                55744   0  [snd-cs4236-lib snd-cs4231-lib]
snd-timer               9744   0  [snd-opl3-lib snd-cs4231-lib snd-pcm]
snd-mpu401-uart         2736   0  [snd-cs4236]
snd-rawmidi            11968   0  [snd-mpu401-uart]
snd-seq-device          3744   0  [snd-opl3-lib snd-rawmidi]
snd                    24576   0  [snd-cs4236 snd-cs4236-lib snd-opl3-lib snd-hwdep snd-cs4231-lib snd-pcm snd-timer snd-mpu401-uart snd-rawmidi snd-seq-device]
soundcore               3632   0  [snd]

Also, after the modprobe works, for the first time you should have a /proc/asound directory, and cat /proc/asound/cards should show something like this:

0 [CS4237B        ]: CS4237B - CS4237B
                     CS4237B at 0x530, irq 5, dma 0&1

Recommendation 7

Now finish building and installing the alsa libraries per the instrutions (unpack the tarballs, enter the directories, execute

./configure && make && make install

Recommendation 8

At this point, even without fiddling with alsamixer, go to a directory with a sound file and type


You should get a message like "Playing WAVE 'horse.wav' : Unsigned 8 bit, Rate 11025 Hz, Mono" if FILENAME (for example) is a wavefile called horse.wav. If in addition you get "aplay: pcm_write:999: write error: Input/output error" then it is likely that your dma's are reversed! In my case, if I got this with the above modprobe, I would remove the snd-cs4236 module:

rmmod -r snd-cs4236

and retry with the dma's switched:

modprobe snd-cs4236 port=0x530 cport=0x538 irq=5 dma1=0 dma2=1

Recommendation 9

OK, now we are in the home stretch. Run alsamixer. <Master D> in the leftmost column should be red. Hit the "M" key on the keyboard to make the MM at the top disappear: otherwise the Master Digital will be muted. Then use the pageup to get the volume up. In my case, I have to get this up almost to the red zone (around 73)-- maybe you don't need as much volume. Then, hit the right arrow six times so PCM is red. Again, unmute it with the "M" key and use pageup to get the volume up (I went to 71).

Now use aplay FILENAME to play FILENAME. It should work.

Recommendation 10

Finally, you should set yourself in the audio group and set up linux to run amixer with the right settings on bootup so the volume is ready to go. You probably want to give the CD player some volume, too.

--Greg Lindauer

More hints

These following steps were needed on a recent installation of Ubuntu Hardy Heron. First, it really likes to try to load cs4232 module, which results in a kernel OOPS. You'll need to use the cs4236 module instead. First, place "blacklist snd_cs4232" to /etc/modprobe.d/blacklist. Then put these commands in /etc/rc.local:

echo 'activate' > /sys/devices/pnp0/00\:0e/resources
echo 'activate' > /sys/devices/pnp0/00\:0f/resources

modprobe snd_cs4236 isapnp=0 port=0x530 cport=0x538 irq=5 dma1=1 dma2=0

See also

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Category: Sound cards

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